For generating power, wind power plants are known for which a generator is driven with the aid of a wind mill that is subjected to the wind. The generated electrical power is then fed into a power grid.
The operators of power grids have specified conditions which must be met by a wind power plant before it can be connected to a power grid. A so-called fault-ride-through condition requires that the wind power plant can continue to feed electrical power into the power grid, even in the event of a short circuit of the power grid. In that case, the voltage drops at the connection point for the wind power plant to a partial voltage or even to zero.
Known is the separate testing, meaning independent of the wind power plant, of electrical components which are used for producing electric power, in particular the generator and, if applicable, the associated converters with the aid of electric simulation circuits. A wind simulation, for example, can be realized with the aid of an electric motor that simulates a desired wind which then acts upon the generator. A grid simulation can furthermore exist which simulates a power grid into which the generator feeds the produced electric power. This grid simulation is connected electrically to the generator or the associated converters. The grid simulation can be influenced in such a way that a desired voltage course for the power grid with adjustable frequency is generated which is then preset in the generator.
The known methods and electrical circuits can simulate a voltage drop toward zero, meaning a short circuit of the power grid. However, the voltage drop can occur only at fixedly predetermined steps and with a fixed frequency.